摘要
通过模型试验探究高承台桩埋藏段存在不同尺寸缺陷时的桩身质点水平速度响应,结合有限元(FEA)分析试验结果.结果表明,基于桩的水平振动特性的低应变检测方法可以用于识别高承台桩桩身缺陷,且缺陷处截面直径越小,桩身质点水平速度响应曲线中缺陷处反射越明显.随着缺陷高度的变化,缺陷处顶、底面反射信号可能会产生叠加或分离现象,导致不同缺陷高度下缺陷反射的波形不一致.在数值模拟中,当采用柔性剪切梁单元模拟高承台桩时,数值模拟结果和试验结果吻合较好.在实际工程中,当应用水平低应变法检测桩身完整性时,推荐采取近承台处激振、近承台处速度采集,可以根据缺陷处反射起振时间较精确地计算桩身缺陷埋深.
The lateral velocity response of an extended pile shaft with defects of various sizes in the buried section was analyzed through model experiment,and the results were analyzed by combining with finite element analysis(FEA)results.Results show that the low-strain integrity test based on the lateral vibration characteristics of the pile can be used to distinguish the defects on extended pile shaft.The smaller the cross-sectional diameter of the defect is,the more obvious the reflection of the defect on the lateral velocity response of the pile is.As the height of the defect changes,the reflection of the top and bottom of the defect may superpose or separate,reflecting waveforms of the defect under different defect heights are inconsistent.The FEA results accorded well with the experimental results when adopting the shear flexible beam element of FEA to simulate the extended pile shaft.It is recommended that the excitation and receiving positions are both near the cap when conducting low-strain integrity test based on the lateral vibration characteristics of the pile.The depth of the defect can be inferred from the arrival time of the reflection of the defect in practical engineering.
作者
赵爽
吴君涛
邱欣晨
王奎华
涂园
ZHAO Shuang;WU Jun-tao;QIU Xin-chen;WANG Kui-hua;TU Yuan(Research Center of Coastal and Urban Geotechnical Engineering,Zhejiang University,Hangzhou 310058,China;Key Laboratory of Soft Soils and Geoenvironmental Engineering of Ministry of Education,Zhejiang University,Hangzhou 310058,China)
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2021年第10期1867-1876,1902,共11页
Journal of Zhejiang University：Engineering Science
基金
国家自然科学基金资助项目(52178358,51779217).
关键词
高承台桩
水平振动
低应变
缺陷检测
extended pile shaft
lateral vibration
low-strain
defect detection
